VintageKustom.com: Repairing Kustom Amps » K200B-2 Both Preamps bad?

Re: K200B-2 Both Preamps bad? [message #26787 is a reply to message #26786]

Tue, 10 July 2018 12:03

chicagobill
Messages: 2005
Registered: April 2003

Senior Member

It sounds like you are on the right track. I often find that I need to replace both input transistors to get a channel working.

The volume control is dc isolated from the circuit by the two caps C103/C104, so unless one of them is shorted, changing the volume control should not change the dc voltages on the input transistors.

What are the other voltages on Q100 and Q101? Are both 8 volt supplies working?

I would resist changing any caps until you prove them to be bad or until you have the channel working and want to upgrade for better sound or reliability. Too many changes can lead you in the wrong direction, which may make the repair harder.

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